Method for producing low-caffeine tea extract

Abstract

To provide a method for reducing a caffeine amount in a caffeine-containing tea extract liquid without deteriorating the original flavor of tea. The present invention provides a method for producing a low-caffeine tea extract, including the steps of: treating a caffeine-containing tea extract with tannase; causing a mixture of non-ester-type catechins and caffeine to be deposited in the caffeine-containing tea extract after the tannase treatment; and separating the deposited mixture for removal. Moreover, the present invention provides a low-caffeine tea extract obtained according to the production method and a food or drink containing the low-caffeine tea extract.

1 . A method for producing a low-caffeine tea extract, comprising the steps of:
 treating a caffeine-containing tea extract with tannase;   causing a mixture of non-ester-type catechins and caffeine to be deposited in the caffeine-containing tea extract after the tannase treatment; and   separating the deposited mixture for removal.   
   
   
       2 . The method for producing the low-caffeine tea extract according to  claim 1 , wherein a proportion (gallate percentage) of ester-type catechins in non-polymer catechins after the tannase treatment is 4% by mass or less. 
   
   
       3 . The method for producing the low-caffeine tea extract according to  claim 1 , wherein a mass ratio of caffeine to the non-polymer catechins in the low-caffeine tea extract is 0 to 0.2. 
   
   
       4 . The method for producing the low-caffeine tea extract according to  claim 1 , wherein the mixture of the non-ester-type catechins and the caffeine is deposited by cooling under conditions of a temperature range from 0 to 25° C. and a time range from 1 to 43 hours. 
   
   
       5 . The method for producing the low-caffeine tea extract according to  claim 1 , wherein the tannase treatment is performed under a condition of a temperature range from 30 to 40° C. 
   
   
       6 . The method for producing the low-caffeine tea extract according to  claim 1 , which is extracted from green tea. 
   
   
       7 . A low-caffeine tea extract obtained by the production method according to  claim 1 . 
   
   
       8 . A food or drink comprising the low-caffeine tea extract according to  claim 7 .